Belt noise on downshift is a loose belt that is trying to suddenly speed up the alternator that is under load when the engine speed rapidly rises during the shift.
As for no power, Does it act the same way in all gears? Did it act this way before the clutch replacement? When was the last time it had a thorough tune up with injector cleaning and fuel filter?
Looking at the engine specifications it looks like a heavy vehicle with a small engine. It is possible the engine is just worn from the years and miles. A compression test. An exhaust back pressure test would show if it is a simple blockage that is reducing the power as well.
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Tuesday, April 11th, 2017 AT 3:58 PM